Zigzag sewing machine with control device for producing composite enclosedarea stitch patterns



D 1964 H. THEENHAUSEN ETAL 3,

ZIGZAG SEWING MACHINE WITH CONTROL DEVICE FOR PRODUCING COMPOSITEENCLOSED-AREA STITCH PATTERNS Original Filed Aug. 12, 1959 9Sheets-Sheet 1 fm emars He/nric/z TAeen/Ia use/1 M /ie/m siebra SS6 Dec.22, 1964 H. THEENHAUSEN ETAL 3,162,156

ZIGZAG SEWING MACHINE WITH CONTROL DEVICE FOR PRODUCING COMPOSITEENCLOSED-AREA STITCH PATTERNS Original Filed Aug. 12 1959 9 Sheets-Sheet2 lm emars e/nr/cb r/ieen/vausen I V/Yfie/m S/ebra. sse

D 1964 H. THEENHAUSEN ETAL 3,

MACHINE WITH DEVICE ZIGZAG SEWING CONTR PRODUCING COMPOSITEENCLOSED-AREA 'TCH PAT NS Original Filed Aug. 12, 1959 9 Sheets-Sheet I5m emans //e fur/c5 T/e en Aause n VV/Me/m siebrasse Dec. 22, 1964 H.THEENHAUSEN ETAL 3,162,156

ZIGZAG SEWING MACHINE WITH CONTROL DEVICE FOR PRODUCING COMPOSITEENCLOSED-AREA STITCH PATTERNS Original Filed Aug. 12, 1959 9Sheets-Sheet 4 Iwenfars He/nr/cfi T/Jeen Aausen D 1964 H. THEENHAUSENETAL 3,162,156

ZIGZAG SEWING MACHINE WITH CONTROL DEVICE FOR PRODUCING COMPOSITEENCLOSED-AREA STITCH PATTERNS Original Filed Aug. 12, 1959 9Sheets-Sheet 5 MANUAL AUIUMAUC' Inventors l //fl r/c/I 7/7een/wau5enWi/Ae/m' S/ bra 5 se Dec. 22, 1964 H. THEENHAUSEN ETAL ZIGZAG SEWINGMACHINE WITH CONTROL DEVICE FOR PRODUCING COMPOSITE ENCLOSED-AREA STITCHPATTERNS Original Filed Aug. 12, 1959 9 Sheets-Sheet 6 I M 2 1+ 193 n102 56 M Inventor's He/hr/Cfi 75s enfia. Us en W/YAe/m S/erasse Dec. 22,1964 H. THEENHAUSEN ETAL 3,162,156

ZIGZAG SEWING MACHINE WITH CONTROL DEVICE FOR PRODUCING COMPOSITEENCLOSED-AREA STITCH PATTERNS Original Filed Aug. 12, 1959 9Sheets-Sheet 7 Heinrich Tfieenhausen m/fie/m sfebr-a. sse

Dec. 22, 1964 H. THEENHAUSEN ETAL 3,162,156

ZIGZAG SEWING MACHINE WITH CONTROL DEVICE FOR PRODUCING COMPOSITEENCLOSEDAREA STITCH PATTERNS Original Filed Aug.

9 Sheets-Sheet 8 illlll fi- 1964 H. THEENHAUSEN ETAL 3,162,156

ZIGZAG sawmc; MACHINE WITH CONTROL DEVICE FOR PRODUCING COMPOSITEENCLOSED-AREA STITCH PATTERNS Original Filed Aug. 12, 1959 9Sheets-Sheet 9 Q M: v 464 Jn vemo 75.

United States Patent 3,l62,l56 Patented Dec. 22, 1964 Our inventionrelates to an automatic zigzag sewing machine with jcontrol means forproducing fancy stitch patterns of theenclosedarea type, particularlybutton holes'f I I\ 'w This application is a division of c opendingapplication Serial No."833,2l6,"filed August 12, 1959 now issued asPatent No. 3,083,657fpatehted April 2, 1 963 There are known zigzagsewing machines in which the stitch width (transverse to the feeddirection), the stitch l engthtin the feed direction), the stitch-areapositiloin' as 'well as thsre'ea' direction are automatically controlledby respective cam disks'driven' from the mechanism of the sewingmachine. Such an automatic sewing machine alfords the production of fanc y stitch patterns that areclosed upon themselves, for example buttoholes. However, in these prior machines the control of the slider whichdetermines the needle-bar position and the feed'direction is relativelyslow and they therefore inevitably produce intermediate stitches whichdo not belong to one or the other component (such as the side bars andthe cross tacks of a buttonhole) bf thep att'ern to be produced, so thatthe appearance of thecornple'ted pattern'is unclean at the transitionlocalities. This'slow control of the needle-bar position and of thematerial feeder device is a consequence" o fth gradu'al ascendingand'descending portions in the contour of 'the'control cams since, inorder to secure the satisfactory function'- ing of all machine parts,these cams "must not possess abrupt transitions.

.The known control devicespermit automatic control of the side-bar andcross-tack stitches and thus produce buttonholes' of different lengths.However, the automaticallyfrot'ating 'set of control earns can bestopped only by stopping the sewing machine'itself or by shifting amanual control member for the stepping switch mechanism .intoitsinactive position. For'these reasons; the person using the machine mustexercise considerable attention for stopping the' set or control camsonly in a definite position of its circumference if he is to prevent asewing over of an already finished seam. Furthermore, when theover-sewing ofa .buttonhole or other pattern completely closed uponitself is completed, it is diflicult with the known device to commencethe sewingof a new buttonhole, because the proper starting point of thenew earn actuated cycle becomesinaccurately located or may have beenpassed, with the result thatthe seams 'of the buttonholes may appearunclean.

It has also beenproposed to produce buttonholes by means ofautomatically rotating control cams in sewing machines in such a mannerthat onlya portion of the entire area pattern is produced automaticallywhereas another portion of the pattern is completed while the controlcams are standstill. For this purpose, the control mechanism is providedwith a cam disk which carries a dog pin for prematurely disconnectingthe cam drive. A special manualsettingmernber is provided to permitthereafter turning the cam disks by hand in o der to complete .theclosed-type sewing pattern, and thereafter to initiate renewed operationof the automatic cam drive.

However, this device does not permit the operator, when us n one a d t sme t ttawa t9 Pr d e butw hole a d tfetent l ngths. be ause far sash. wese t re is a predetermined'constant transmission ratio between the armtai an the driv Sha t e pt t 'qn 9f t individual control earns It i eefqr a 9111's. 9 1? vsi t q t improve confrbl devices f s abat -mammal Win Zi za sewing r nachine s i l Such manner as to facilitate and improvethe production of butt onholes or other enclosed- -sa Pa rn b mean Ptamateur t t n I 'w i fal e c in m r a c ate nd leaner iPPamIi-c-b b'fih"atten??? 9 t 'si PW??? .fiibQ placing"'eitacting'requireni'ents up'or'the attention or skill 0f h n a ing S w n r connaiit "isia f fi r therobject qtt'he invention to provide a control d evice fdr azigz'ag sewingefife'cts' e1 hv fi h a tiaa v t h 9 mm! a froni'orielcontrol"secttir ofaca 'n, which produces one portioii' of a com ound pattern," to nswer"ej n rqi sector Of the control cam produces another "portionofewiiig'cycles, or between portions of the same sewing cy l whileretainin a gradual contour change in the shape of the cam surfaceitself.

.4 achieve thes bie ts. our in entio is p di d upon theuse ofazigza'g's'e'wing' machine with'a'n automatic control deyice to; theproduction of closed ar ea stitch patternsfpart A, 1y butt h with theaid of a r0- sefof earns for a atically'cbrltrolling' the tat needle-barmovements and the feedof the" material bein'g sewq Ma hia s .of hi eeral pe a e m e u y described incopending applications Serial Nos.514,178, 15.1 $359 and 555 55. all en m to' as? sign'ee of'the presentinvention, noW USfPfa tent' Nos. 22 ,34 3 53 253 iii! 3,05 ,3 31 iv llymange su h were it i a feature P our 'inventiori to prhvideja'circularlyacting force storing devieebetween the portion of the con 01 mea sdriven from the arm s attiof t; ri1 a h rie on the onehand and the setof cani's' for controlli the stitching width, the stitchfi a lft' l fibi i 'o er h a he a e s eer having theetfect'of producing anahruptswitching of "sector.

virtue of'the abrupt jump in the control of the cams,

from one control sector to the next, any possibility of intermediate's't'itches'fo rming between the individual patlerii stit es proper;suchas'the side-barstitches and the cross tac'k stitches offa butt nholeis eliminated.

In o r'der t'o alvjoidturtlherdisadvantages of the knownmethddshnddfidsfor producing closed patterns such asb'u'ttoriho'ies by'means "of "automatically iotating control c'arnsQWe' further provide,according to another feature of our invention, an automatic couplingdevice which renders the'drivin'g 'me'ans selectively activeand inactivein one and'thsaine pb sition of t-he set of cam disks." The'lattefrffe'ature'afiordsthe 'considera'ble advantage withautomatically" rptating control that certain sewing-stitch patterns,foi" erian ple the last side-bar stitches fa but'tonliqlefarecontrolled'while the set of cams'is "at 'sta This is particularlysignificant in viewer the fact th at diifer'ent fabrics or othermaterials to be sewed are subjectedto respectively different {amounts offeed niotion even though the'cam control may call for a constant feed.Furthermore, differences may occur between the forward and reversetravel of the fabric when producing enclQsed-area stitch patterns, andsuch difference scan be compensated for with the present invention byvirtue of the tact that the last portion of the sewing travel iscontrollable while theset of cams remains at rest.

' cation.

-quired for zigzag; operation. These lateral movements The inventionwill be further described with reference to two embodiments of controldevices according to the invention, illustrated by way of example on theaccompanying drawings, in which:

FIG. 1 is a cross-sectional view of the first control device, thesection being taken along the line A-B indicated'in FIG. 4.

FIG. 2 show a top view of the same device, and

FIGS' is a lateral view of the device.

FIG. 4 illustrates a top view of the device partly in cross sectionalong the line C-D indicated in FIG. 1.

FIGS. 5 and 6 are top views cut away to show details of the same controldevice. 7

FIG. 7 is a sectional top view onto part of the sewing machine of FIG.14 with the top housing removed to show the control device forpositioning of the stitching area and for the motif frequency.

FIG. 8 is a lateral, sectional view of the control device for theposition of the stitching area, the section being taken along the lineVIII-VIII indicated in FIG. 7.

FIG. 9 shows, partly in section, a separate top view of a steppingmechanism which forms part of the same devices as represented in FIG. 7.

FIG. 10 is a partly sectional view of the automatic control device forthe stitching-area position, the stitching width, and the material feed.

FIG. 11 is a partially sectional view of the coupling device. 1

FIG. 12 shows in lateral view the automatic contro device for thestitching-area position, the stitching width, and the feed.

FIG. 13 shows the device of FIG. 2 in plan view.

FIG. 14 is a front View, seen from the operators position, of a zigzagsewing machine according to the invention. I

FIG. 15 is a related parts.

FIG. 16 is a fragmentary front view, in section, of the material feedingdevice.

In the copending application Serial No. 515,160, filed June 13, 1955, byHeinrich Theenhauser and Otto Wank, assigned to the assignee of thepresent invention, there is described a zigzag sewing machine whosecontrol cams are driven from the arm shaft by means of a cam mechanisrn,with a stepping switch and a roller coupling interposed between the armshaft and the camshaft. The embodiments illustrated in the presentapplication and described presently relate. generally to a machine ofthe type illustrated and described 'in that copending appliplan view ofthe stitch control fork and In accordance with the conventional designof sewing machines, those illustrated and described herein have a base 8(FIG. 14) onwhich a machine housing is mounted. This housing 55 forms ahollow standard joined with the'base and has a horizontal hollow armportion 52a (FIGS. 7, 8), which remote from the standard, merges with adependent needle-bar housing located above, and upwardly spaced from thesewing area on the top surface of the base. The interior of the housing55 comprises the needle-bar drive mechanism as well as most of the partsappertaining to the control mechanism according to the invention. Theopen top of the housing is closed by a hinged or. removable cover 115a.The conventional presser foot C forms an exchangeable part of anassembly I) which extend vertically upward into the housing where itcomprises a verticalrrod P, shown in FIGS.14 and 15. As usual, thepresser-foot assembly can be lifted and lowered. The verticallyreciprocable'needle bar N (FIGS. l4, 15) carrying the sewing needle Mextends parallel to the presser-foot assembly. Its operation forstraight sewing is. as usual and 'is therefore not further described.

Aside fromits vertical reciprocations, the needle barv T N is alsocapable of lateral swinging movements as reoccur about the axis of theresser-foot rod P in a horizontal direction substantially parallel tothe plane of illustration of FIG. 14, and they are accompanied by acorresponding swinging movement of the presser foot. The needle bar N isvertically slidable in a bearing sleeve S (FIG. 15). Sleeve S forms partof a swing frame F which is mounted on the presser-foot rod P and isrotatable together with rod P about the vertical axis of rod P. Duringstraight sewing the swing frame F is stationary, but for zigzag work anoscillating motion is imparted to the frame F by means of a connectingrod R which extends through the horizontal arm portion 52a of themachine housing 55 to an assembly of control mechanisms mounted in thehousing.

It will be recognized from FIG. 15 that the zigzag stitching width inthe directions of the double-headed arrow A corresponds to the amplitudeof any oscillations transmitted by rod R to swing frame F, and that thesticking location or area is determined by the center or zero positionof these oscillations. The stitch controlling oscillations come aboutand are controlled as follows:

During the machine operation, a continuously rotating cam 349 acts uponglide faces of a stitch control fork 348 with which the rod R isconnected. The fork 343 has a pivot pin 347 on which a slide block 346is revolvable. The slider 346 is guided in a groove (shown in brokenlines) of a slideway member 345. Member 345 is dis placeable in twoways, namely angularly about its axis and also linearly. Assume firstthat the member 345 occupies the illustrated position of FIG. 15 inwhich its groove has the direction of the indicated axis 0O. When thecam 349 is rotating, the fork 348 and rod R will oscillate about theaxis of the needle bar N while the slide block 346 will reciprocatealong the groove of memher 345. Hence no swinging motion is transmittedto the needle bar and the lateral stitching width is zero.

Now assume that the member 345 is turned clockwise (as viewed in FIG. 15so that the groove extends along the axis T-T. Then during theoscillations of fork 348 a lateral component of motion is transmittedthrough rod R to the swing frame F so that the needle bar N willoscillate about the axis of presser-foot rod P with an amplitudedependent upon the amount of angular displace ment of member 345 fromthe zero axis 0O. In this manner, any desired amplitude and hencestitching width can be adjusted within the available range. The angularadjustment of slide-way member 345 is effected either manually bysetting a width control knob W (FIG. 14) or automatically by operationof a selected, exchangeable cam disk 1% (FIG. 10), depending uponwhether a control member 59 is placed in manual" or automatic" position.

, Referring to FIG. 15, the slide-way member 345 is further capable oflinear displacement toward or away from the presser-foot rod P. Any suchdisplacement is shared by the pivot pin 347 of the stitch control fork34% so that the center position or area of the oscillations transmittedfrom cam 349 to the needle bar N is shifted accordingly. The slidewaymember 345 has a pivot mounted on a slide plate 336 (FIG. 7), and thisplate can be shifted either manually by a control lever 56, 59 (FIGS. 8,14) or by the cam disk 193 acting through link 3116, thus controllingthe stitching area.

The automatic control'of the material feed is carried out by the camdisk 1% acting upon the feeder fork arm 462 (FIG. 16) through the mediumof cam feeler lever 124 and through a series of linkages such as aremore fully described and illustrated in the above-mentioned copendingapplication Serial No. 665,555 of Albert Klaar et al., assigned to theassignee of the present invention. During rotation of the arm shaft 346a(FIG. l4) an eccentric (not illustrated) imparts lateral deflections tothe feeder fork 462. Depending upon the position of a movable block (notillustrated), the feeding fork 462. then deflects in its longitudinaldirection or transversely 5 thereto as determined. by. its guidance in aslideway of the aforementioned. movable bloek. The lifting motion, con:strainedly following therefrom, is transmitted through the crank 463 andthe shaft asp. onto the feeder crank 465 (FIG. 16) which acts upon thematerial pusher. 467 through the pusher carrier 4 56 The. device shownparti ularly in FIGS, 1 to 6 serves for automatically controlling theproduetion 'of stitch patterns which are closed upon themselves,andrparticularly for the production of buttonholes which are cornposedof two side bars along the buttonhole opening and two cross tacks at therespective: ends of the buttonhole. The drive shaft 1 (FIG. 1) of thecontrol device has a central bore 2 engaged by. a stub shaft 3 drivenpreferably from a stepping mechanism as exemplified by the one shown inFIG. 9 and described further'below. The stub shaft 3 is journalled inthe arm structure 4 of the sewing machine and, when in operation,entr'ains the drive shaftt 1 for stepwise motion. The drive shaft 1forms several steps with annular shoulders and is guided in thecorrespondingly stepped base plate 6 of the mechanism. The base plate 6is firmly secured to the machine arm 4 by bolts or other suitable means(not illustrated). The cam disks 8, 9 and 11 are rotatably journalled'on the extension 7 of the drive shaft and these disks are, namely a camdisk 8 for controlling the stitching area position, a cam disk 9 forcontrolling the stitching width, and a cam disk all for controlling thestitching length and the feed direction. The cams cooperate withrespective cam followers 11, 1 2 and 13 (FIG. 4) and are connected by ascrew bolt 1% (FIG/ 1) with a control member 15 mounted on drive shaftand designed as described below to serve as a spring housing. Locatedthe member 15 is a spiral spring serving as a force storer. Theinnermost turn 17 of spring 16 is provided with a rectangular hole 18(FIG. 4) engaged by an entrainer wedge 19 of the drive shaft 1, Theoutermost turn 20 of the spiral spring 16 is fastened to the innerwall21 of the control member 15. A sleeve 24, fastened to drive shaft 1by means of a clamping plate 22 a screw 23, c ver e pri 1. s Wel as aiio 9 n member 15. i

Riveted to the base plate b (FIG. 1) is a pin 25 upon which a sleeve 26is seated. Joined with thesleeve 26 is a latch lever with two arms 27anad 3 1 (FIG. 2) which, together with sleeve 26, can perform pivotalmotion about the axis of pin 25. The latch lever has a bore 28 in leverarm 27 (FIGS. 2, 5, 6) engaged by one end of a helical spring 31} whoseother end abuts against a pin 2? fastened to .the base plate 6 Figs. 3,6). The spring imposes .11 th la ch e e 27 31 a biasi force th clo kw sdirection relative to FIG. 2 so that a latch nose' 32 of lever arm 31can catch behind a stop 34 :(FIGS'Z, of control member 15, the stop 34constisting of rubber or synthetic material.

Disposed on the outer periphery of control member 15 are further .stops35 to 38 (FIG. 2) corresponding .to fur ther closed-type stitch patternsto be produced. Rotatahly seated on the sleeve-26 (FIG. 1) is areleaselever 3? (FIGS. 1, 2, 5, 6) whichisadjustable on the .arm 31 ofthe latch lever by .means of a screw 40. The levers 27, '31 and 39 areprevented from axial displacement by means of a lock washer 42 engaginga peripheral groove .41 of the pivotpin 25. v

The release lever 39 has anose cooperating withdogs 44 to 47 which aremounted on the periphery of thesleeve 24 and are .displaceablealong the'periphery and adapted to be fastened in the, properpositions byrmeansof fastening screws 48, 49. The arm 27 of latch lever 27, 3 1 mergesinto a hook-shaped latch no se 50 for cooperation with the stops34 to38. .The latchlever 27, 31 carries a manually actuable extension :51(F1652, 5, 6) which serves to adjust thestarting point of acompoundstitch pattern, such starting point beingfor example, the first side barof a buttonhole. The upper portion 52 of sleeve 2}! (FIG. 3) is knurledto facilitate manual manipulation.

The operation or the control device described so far is as follows. r ii The shaft 1 of the control device is driven counterclockwise relativeto'FIG. 4 from'the arm shaft 346a (FIG. 14) through conventional means,preferably worm gears, and through an intermediate stepping mechanism 91(FIG. 9) acting through step shaft 3," At the beginning of the sewingoperation for producing a buttonhole, S ch counterclockwise rotation ofshaft 1 places the spiral spring 16 underlension by means of theentrainer wedge 19 mounted on shaft 1. The spiral spring 16 has a slightinitial tension and becomes wound up when the shaft 1 with its wedge 19comme'ncesrotatirig counterclockwise (relative to'FlGQ 4). The controlmember 15, which forms the housing for the spiral'spring 16, isprevented from rotating by in QIlS 0f the stop 3-3 (FlG. 2, 5) which isengaged by the latch nose 32 of the latch lever 27, 31 biased clockwise(relative to FIG; 5) by the helical spring 3% (FIG. 1, 3) Consequently,the control cams 8, 9 and'llil, and thus also their respective followers11,12 and 13 (FI GQ 4) are kept arrested in their starting positionswhile the first side bar of a buttonhole is beingproduced, namely in thefirst control position of the control 5 gand 1 As soon as the nose 4 3of release lever 39 runs onto the slan ting do g 44- of'the'sl'eeve 24driven counterclockwise from shaft 1 (relativeto FIGS. 2, 5, 6), thelatch nose 32 of latch lever 27, 31 is withdrawn from the stop 34 of thecontrol member 15. As a result, the control member 15, carrying'thecontrol cams 8, 9, 10, is turned counterclockwise (relative to FIGS. 2,5 and 6) by the action of the force-storing spring 16 to such an extentthat the stop 38 of controlmember 15 is caught by the hook-shaped latchnose 5!} of lever arm 27, thus preventing a further rotationof thecontrol'membcr 1 5. rotary motion of control member 15 from nose 32 tonose'50, however, is so slight that it does not'release anyswitching'm'overn'ent of the control cams 8, 9 and 10. As soon as thedog 44 has runbeyond the nose 43of release lever'39, lever 39 has beenpivoted counterclockwise to disengage latch nose 32' from stop 34. Thecontrol member 15 ,'biase d by the drivingforce of the wound-upspiralspring 16, is thus released and turns impactwise incounterclockwise direction until the stop 35 (FIG. 2) abuts against thelatchnose 32of latch lever arm 27. This rotary jump of member 15 causesan abrupt rotaryswitching of the cam surfaces of control cams 8,9 and10, relative to their 'cam followers, from the first to the second camcontrol position, the latter of which controls the stitching of thefirst cr'oss'tack of the buttonhole. This abrupt switching'of the camsprevents the. formation of undesirable intermediate stitches that belongneither to the first side bar nor the first cross tack of the buttonholebeing sewn.

Since, in comparison to the side bars of the buttonhole, only a 'fewcross-tack stitches must be made, the pair of dogs 44 and 45 forproducing the required control movements, as well as the pair of dogs46'and 4-7 which follow at some distance therefrom, are located closelybehind each other and the relative location of each pair of dogsalong'the peripher 'or the sleeve 24- is adjustable by means ofrespective screws 48, 19 for permitting a correction of the individualbuttonhole side-bar lengths.

The next following control operations for producing the second sidebar'and the second cross tack as well as the final sewing-over of thebuttonhole take place in a manner analogous to that described above.'The drive shaft 1 performs a single full revolution during production ofasingle buttonhole. For that reason, alls'top's' 34 to 38 of eachcontrol member 15 come into engagement once with the latch noses 32 andSdof. the latch-lever arms 27,

31. After completion of a full revolution of the drive shaft 1, thecontrol member 15 with control cams 8, Q9 and 10 has .also performed afull revolution so the Pretensioning of the spiral spring 16, adjustedwith such pre-tension prior to the first control operation, ispreserved. e p

The handle portion 51 of the latch lever 37, 31 as well as the knurledportion 52 of the sleeve 24 can be actuated in order to adjust thebeginning location of a stitching pattern (in the present example thestart of the first side bar of a buttonhole) and also to adjust thepre-tension of the spiral spring 16.

According to another feature or sub-combination of the invention, thearm structure 52a (FIG. 7) of the sewing machine is provided with aslider 53 which permits manual adjustment of the stitching-area positionand adjustment of the automatic control of that position.- The slider59(FlGS. 7, 8) is displaceably mounted on an arm 56 whose hub 57 isconcentrically seated on a sleeve-53 fastened on a base plate 16:; (FIG.8). The arm 56 controls the slider block of the control mechanism inknown manner.

FIG. 8 corresponds, generally, toFIG. 21 of copending application SerialNo. 665,555 of Klaar et al., assigned to the assignee of the presentinvention, and the detailed description of the components thereinillustrated are more fully described in that copending application.However, for purposes of better understanding the-present invention, adescription of the slider 59 and control member 56 is also includedbelow.

The slider 59 is displaceably mounted on the arm 56 and carries a nose60 (FIG. 8) which cooperates with a recess 61 in an arresting or stopplate 62. The arresting plate 62 is fastened by screws on a stop member63 (FIGS. 7, 8). The stop member 63 is'fastened to the carrier plate1641 which in turn is fastened to the machine arm structure 52a. Theslider, 59 carries a trans mission coupling member or pin 65coacting'with a recess 66 of a lever 67 (FIG. 7). Lever 67 is rigidlyjoined with the pivot'shaft 68 rotatably journalled in the sleeve '53,fixed to the plate 16a. When the slider 59 is placed into manualposition M (FIG. 7), the nose 60 comes into engagement with the stopplate 62, thus placing the pin 65 out of its active position. When theslider is placed into automatic position A (FIG. 7), the pin 65 becomescoupled with the lever 67 and the nose 611 is placed out of its activeposition, thus effecting automatic control of the stitching'area bymeans of link 116, a carn disk, and a slide block, to displace theneedle bar N (FIG. 14) in accordance with the adjusted stitching area,as

'more fully described in the above-mentioned copending applicationSerial No. 665,555.

The device driving the cam disks that control the needlebar movementsandfeed is also known and is described in the above-mentioned copendingapplications assigned to the present assignee. Consequently thesedevices-are described hereinafter only to the extent needed for abetterunderstanding of the present invention.

The device shown. in FIGS. 7 to 9 has a shaft 353 (FIGS; 9, l) drivenfrom the main shaft in the arm structure of the sewing machine. Theshaft 353 carries a double eccentric 69 (FIG. 9) acting upon an arm 71?of a bifurcated swing lever 71 which is biased counterclockwise by aspring 72 (FIGS. 7, 9) and serves as the driver of a stepping mechanismformed by a roller clutch 91. The bifurcated portion of swing lever 71engages adriving roller 88 pivoted on the driven oscillating drivestructure of the roller clutch. a

The swing lever '71 is pivoted by means of a bushing 73 on apivot pin 74riveted to an arm (FIG.- 7). The arm 75 carries a pivot pin7 which isrotatably mounted onthe plate 1 6a and is firmly connected by ascrew 73with an arm 77 (1 18.7). A boss 79 in arm 77 guides itself beneath'aslide bridge 81 Arm 77 carries a handle '76 causes a correspondingangular displacement of the arm and of the pivot pin 74 of swing lever71, thus varying the active leverage of swing lever 71. In thismanner,the rotating speed of the stepping mechanism 5 1 can be manuallycontrolled.

The stepping mechanism 31 (FIG. 7) drives the abovedescribed cam driveshaft 3 (FIGS. 1, 3, 7, 9). The cams 8, 9, 1@ (FIG. 3) cooperate, asalready mentioned, with the follower levers 11, 12, 13 respectively. Asshown in FIG. 7, the cam 8 for the automatic control of thestitching-area position is in driving connection with the nose 114 (FlG.7) of the feeler lever 11. Connected with the feeler lever 11 by meansof a screw bolt 117 is a lever arm 116 whose other end is linked to theabovementioned lever 67 by means of the bolt 118. A spring 119 acts uponthe lever and biases the feeler lever 11 clockwise So that its nose 114is held against the contour of cam disc 8.

For removing from the drive shaft 3 the cam discs 3, 9, 1t) and thestepping mechanism in connection therewith, there is provided a lever187 which is pivoted on a stationary pin 191 and acts upon theextensions 184 of the feeler levers 11, 12, 13 in order to lift them offthe cam discs 3, 9, 111. I

In the embodiment of FIGS. 10-13, the shaft 191, corresponding to shaft3 of FIGS. 1-9, has a key engaging a groove 103 of a bushing 3119 placedupon the drive shaft 1111. The bushing 39% has a flange portion 301(FIG. 10) and is rigidly joined together with a toothed or serrated disk305 by a cross pin 3M (FIGS. 1O, 11, 12, 13). The disk 305 carries onthe lower side of its cylinder-shaped portion 306 a circle of saw-liketeeth 3 7 engaged by an entrainer 3118 (FIG. 11) of a coupling lever3199. The lever 309, made of spring steel for resiliency, hasring-shaped configuration and comprises a sector 312 fastened on flange310 by means of rivets 311 (FIG. 12) which merges with an outwardlyextending sector 313 having a stop finger 314 and the above-mentionedentrainer 308. Fastened to the flange 310 by means of screws 315 (FIG.10) are the cam disks 192, 1% and 194 which coact with the cam followers187, 115, 124 (FIG. 13) and serve for controlling the stitching width,the stitching-area position and the material feed respectively. The camdisks 192, 133, 194- and the flange 311 are freewheelingly seated on thebushing 311i) and form together with the coupling lever 309, the tootheddisk 3115, and the bushing 3% an independent structural unit which canreadily be installed onto the drive shaft 131 and can easily beexchanged for another set of cams. The individual cam disks 192, 193,194 can be given such a cam surface contour that they automaticallycontrol the individual side-bar. and cross-tack stitches of a buttonholeor other sewing pattern as well as the sewing-over operation during asingle full rotation of the cam shaft.

The finger 314 of coupling lever 339 (FIGS. 11, 13) acts upon a stop 317which is fastened by means of a screw 3116 upon a cam follower or feelerlever 115 (FIGS. 7 13) for the automatic control of the stitching-areaposition. The stop 317 comprises a straight portion 313 and a portion319 which extends angularly in the upward direction and is skewed initself. The follower levers 107, 115 and 124 are pivotally mounted onplate 16a by means of a pivot pin 122 and carry respective extensions133, 184, acted upon by a release lever 137. The release lever 187 isrotatable about a fixed pivot pin 191 and serves for lifting thefollower levers 1417, 115, 124 off the respective cam disks 192, 193,194 when the set of cam disks is being exchanged for another set.

As mentioned, the cam disk 193 (FIG. 12) cooperates with the nose 114 ofthe follower lever 115 for control of the stitching-area position.Connected with the follower 115 by a screw 117 is a link 116 whose otherend is pivotally connected by a bolt 118 with the lever 67. A spring 119acting upon the link 116 urges the follower 115 clockwise until the nose114 abuts against the cam contour of cam disk 193.

- The operation of the device described above with reference'to FIGS. 7to 13 isas follows.

When producing closed groups of stitch patterns, for example buttonholesin a shirt, by virtue of the automatic control performance of the set ofcam disks 192, 193, 194, the rotating speed of the cam shaft 3 must beconstant even though this shaft is driven from the arm shaft of themachine through a stepping mechanism 91. A change in the setting of thehandle 80 (FIG. '7 would change the driving speed of the cam disks 192,193, 194 and hence the longitudinal dimension of the buttonhole beingproduced. At the beginning of the sewing operation, the cam shaft 3,acting throughthe bushing 30% (FIG. rotates the toothed disk 305 in acounterclockwise direction, as viewed in FIG. 13. Due to the elasticityof the freely movable coupling lever 399, is biased upwardly so that theentrainer 308 of lever 3%9 engages one gap of the saw teeth 307 andthereby entrains the coupling lever 369 as well as the cam disks 192,193, 194 in the same sense of rotation as disk 305.

Shortly before, or at the moment of, the termination of the sewingoperation cycle during which the first side bar, the first cross tack,the second side bar and the second cross tack of the buttonhole havebeen sewed and the completed buttonhole may have been sewed over as thelast step of the cycle, the finger 314 of coupling lever 309 passesbeneath the portion 319 of the upwardly extending stop 317 on followerlever 115. Finger 314 is thus forced downwardly, relative to FIG. 12,i.e. at right angles to the circular motion path of finger 314, so thatthe entrainer 398 disengages itself from the teeth 307, therebyimmediately stopping the flange 314 and the cam disks 192, 193, 194connected thereto, but without thereby interrupting the rotation of thedrive shaft 101.

Tht contour desi n of the cam disk may be so chosen that the cam drivingmotion is terminated immediately before termination of the last sewingoperation, that is prior to terminating the sewing-over step, with theresult that the seamstress has sufiicient time to bring the sewingmachine to a standstill. However, if a sewing-over operation on thebuttonhole is not desired, then the drive of the cam disk may beinterrupted, for example, when passing from cross-tack sewing to thesewing of the next following side bar.

After completing the buttonhole in standstill condition of the camdisks, and after selecting the next location on the fabric to beprovided with another buttonhole, the slider 59, placed in automaticposition A, is manually moved together with its arm 56 toward the rightrelative to the illustration in FIG. 7. This causes the link 116 to turnthe cam follower 115 with the stop 317 counterclockwise about the pivotpoint 122 (FIGS. 7, 13) in opposition to the action of the tensionspring 119. As a result, the finger 314 of the coupling lever 399 isreleased from under the part 319 and, due to its elastic pre-tensioning,is flung upwardly thus resuming its coupling position. In this position,the entrainer 398 again engages the saw teeth 307. The engagement mayoccur in any position of the toothed disk 305. When the slider 59returns to its original position, relative to FIG. 7, the part 319 ofstop 317 is shoved beneath the finger 314 of coupling lever 309 withoutdisturbing the motion of the coupling lever at the beginning of thefollowing machine operation.

It is, of course, possible and within the scope of the invention, tomount the control cam 192 for the stitching width or the control cam 194for the material feed in such a manner, and in lieu of the cam disk 193for theautomatic control of the stitching-area position, that theappertaining follower lever 197 or 124 is provided with the stop for thecoupling lever3tl9. Thus, with an analogous design of the correlated,not illustrated, manual control switching means, the coupling lever 309and the cam disks 192, 193, 194- can be controlled in the same manner asdescribed above with reference to the control effected by. the cam disk193.

10 Although the impact actuating means 16 has herein been illusrated' asa spiral springv for storing mechanical energy, it is also within thescope of this invention, and will be apparent to those skilled in theart upon reading of this disclosure, that other impact actuating means,

such as, for example, electrically controlled actuating means operatedby solenoid or the like, can be used as means for actuating the releaselever 39 or for rotating the control member 15 at the proper time in thecycle of cams 8, 9, 10.

It will be understood by those skilled in the art, upon a study of thisdisclosure, that the invetion is not limited to the embodimentsparticularly illustrated and described herein but may be modified invarious respects without departing from the esesntial features of theinvention and within the scope of the claims annexed hereto.

We claim:

1. In a zigzag sewing machine, the combination of a material feeddevice, an axially reciprocable needle bar laterally oscillatable forproducing lateral stitches, automatic control apparatus having rotarycam means and operably linked to said material feed device and to saidneedle bar to control the rate of feeding of the material being sewed onand thereby the stitching length, and to move the needle bar laterallyto control the stitching area and stitching width of saidlateral-stitches, drive means arranged to reciprocate said needle bar.and to turn said rotary cam means, transmission means of variable speedratio operably and disengageably connected to said drive means to turnsaid rotary cam means in variable speed correlation with thereciprocating movements of said needle bar, a select-ably exchangeablecam element rota tably arranged to be turned by said transmission means,manual setting means operably connected to said transmission means forselectively setting the ratio thereof, said manual setting means havinga transmission coupling member operable, in one predetermined positionof said manual setting means, to disengage said transmission means fromsaid said drive means for manual control of said lateral oscillations ofsaid needle bar, said selectably exchangeable cam element having a camsurface and cam follower means cooperative therewith operatively linkedto said transmission coupling member to move said manual setting meansto said predetermined position to disengage said transmission means, acoupling device comprising a disk having a cylindrical portion,entraining means comprising a coupling lever for disenageably entrainingsaid cylindrical portion, said coupling lever being joined to said cammeans for rotation therewith, mount ing means removably mountablerelative to said transmission means and rotatably joined to saidselectably exchangeable cam element, said mounting means, said couplinglever and said disk forming together an independent structural unitbodily removable from said transmission means, whereby said manualsetting means serves for manual control of the stitching area position,for switching from manual to automatic control of the stitching areaposition, and also for switching on the automatic drive of said cammeans from said drive means through said transmission means.

2. In a zigzag sewing machine according to claim 1, said coupling leverbeing operably connected to said cam element for disengageably drivingthe latter from said drive means, stop means for engaging said couplinglever and thus disengaging same from said drive means to arrest said camelement upon completion of a predetermined cycle of the latter, biasingmeans for urging said cam follower means against said cam element andfor urging said manual setting means in a predetermined direction,whereby motion of said manual setting means operably linked to said camfollowerer means in a direction opposite to said predetermined directionand against the force .of said biasing means causes said engaging meanson said cam follower means to release said coupling lever from itsengaged position with said stop means and thus to again engage saidcoupling lever with said drive means for further rotation of said camelement.

3. In a zigzag sewing machine according to claim 1, said drive meanshaving a drive shaft operably and disengageably connected to said rotarycam means through said coupling lever, whereby when said entrainingmeans are disengaged from entraining said disk said drive shaft of saiddrive means continues to rotate while saidrotary cam means are inarrested condition.

4. In a zigzag sewing machine according to claim 1, said cylindricalportion of said disk of said coupling device being provided withserrations and said coupling lever being adapted for engaging anddisengaging said serrations, said mounting means comprising a bushingnonrotatably joined with said cylindrical portion and on which saidrotary cam'means are rotatably mounted, said bushing having key meansfor positive driving connection with said 'drivemeans through saidtransmission means,

and said coupling lever having flange means fixedly at-' tached to saidrotary cam means.

In a zigzag sewing machine, the combination of a material feed device,an axially reciprocable needle bar laterally oscillatable for producinglateral stitches, automatic control apparatus having rotary cam meansand cam follower means and operably linked to said material feed deviceand to said needle bar to control the rate of feeding of the materialbeing sewed on and thereby the stitching length, and to move the needlebar laterally to control the stitching area and stitching Width of saidlateral stitches, drive means arranged to reciprocate said needle barand to turn said rotary cam means, a coupling device engageable betweensaid drive means and said rotary cam means for drivingly coupling anduncoupling the latter, said coupling device comprising a disk having aserrated cylindrical portion, entertaining means arranged for rotationwith said rotary cam means and comprising a coupling lever having acircular portion provided with a tooth entertainer fixed thereon forengaging said serrated portion and movable with the latter in entrainedposition along a predetermined path, resilient stop means forming anextension of said coupling lever, deflecting means on said cam followermeans for deflecting and placing a stressing force upon said resilientstop means in a direction at right angles to said predetermined path todisengage said tooth entrainer from said serrated portion and thus touncouple said coupling device, and manually operable means fordisengaging said deflecting means from said resilient stop means,whereby said stressing force is eliminated and said resilient stop meanssprings back to engage said tooth entrainer with said serrated portionand thus to place said coupling device back into coupled position.

6. In a zigzag sewing machine according to claim 5, said serratedcylindrical portion of said disk and said tooth entrainer beingengageable and disengageable in any mutual position thereof, wherebysaid coupling device can be coupled and uncoupled at any portion of thecycle of said rotary cam means.

References Cited in the tile of this patent UNITED STATES PATENTSTheenhausen et. al Jan. 3 1961 3,055,324 Klaar et al Sept. 25, 1962

1. IN A ZIGZAG SEWING MACHINE, THE COMBINATION OF A MATERIAL FEEDDEVICE, AN AXIALLY RECIPROCABLE NEEDLE BAR LATERALLY OSCILLATABLE FORPRODUCING LATERAL STITCHES, AUTOMATIC CONTROL APPARATUS HAVING ROTARYCAM MEANS AND OPERABLY LINKED TO SAID MATERIAL FEED DEVICE AND TO SAIDNEEDLE BAR TO CONTROL THE RATE OF FEEDING OF THE MATERIAL BEING SEWED ONAND THEREBY THE STITCHING LENGTH, AND TO MOVE THE NEEDLE BAR LATERALLYTO CONTROL THE STITCHING AREA AND STITCHING WIDTH OF SAID LATERALSTITCHES, DRIVE MEANS ARRANGED TO RECIPROCATE SAID NEEDLE BAR AND TOTURN SAID ROTARY CAM MEANS, TRANSMISSION MEANS OF VARIABLE SPEED RATIOOPERABLY AND DISENGAGEABLY CONNECTED TO SAID DRIVE MEANS TO TURN SAIDROTARY CAM MEANS IN VARIABLE SPEED CORRELATION WITH THE RECIPROCATINGMOVEMENTS OF SAID NEEDLE BAR, A SELECTABLY EXCHANGEABLE CAM ELEMENTROTATABLY ARRANGED TO BE TURNED BY SAID TRANSMISSION MEANS, MANUALSETTING MEANS OPERABLY CONNECTED TO SAID TRANSMISSION MEANS FORSELECTIVELY SETTING THE RATIO THEREOF, SAID MANUAL SETTING MEANS HAVINGA TRANSMISSION COUPLING MEMBER OPERABLE, IN ONE PREDETERMINED POSITIONOF SAID MANUAL SETTING MEANS, TO DISENGAGE SAID TRANSMISSION MEANS FROMSAID DRIVE MEANS FOR MANUAL CONTROL OF SAID LATERAL OSCILLATIONS OF SAIDNEEDLE BAR, SAID SELECTABLY EXCHANGEABLE CAM ELEMENT HAVING A CAMSURFACE AND CAM FOLLOWER MEANS COOPERATIVE THEREWITH OPERATIVELY LINKEDTO SAID TRANSMISSION COUPLING MEMBER TO MOVE SAID MANUAL SETTING MEANSTO SAID PREDETERMINED POSITION TO DISENGAGE SAID TRANSMISSION MEANS, ACOUPLING DEVICE COMPRISING A DISK HAVING A CYLINDRICAL PORTION,ENTRAINING MEANS COMPRISING A COUPLING LEVER FOR DISENAGEABLY ENTRAININGSAID CYLINDRICAL PORTION, SAID COUPLING LEVER BEING JOINED TO SAID CAMMEANS FOR ROTATION THEREWITH, MOUNTING MEANS REMOVABLY MOUNTABLERELATIVE TO SAID TRANSMISSION MEANS AND ROTATABLY JOINED TO SAIDSELECTABLY EXCHANGEABLE CAM ELEMENT, SAID MOUNTING MEANS, SAID COUPLINGLEVER AND SAID DISK FORMING TOGETHER AN INDEPENDENT STRUCTURAL UNITBODILY REMOVABLE FROM SAID TRANSMISSION MEANS, WHEREBY SAID MANUALSETTING MEANS SERVES FOR MANUAL CONTROL OF THE STITCHING AREA POSITION,FOR SWITCHING FROM MANUAL TO AUTOMATIC CONTROL OF THE STITCHING AREAPOSITION, AND ALSO FOR SWITCHING ON THE AUTOMATIC DRIVE OF SAID CAMMEANS FROM SAID DRIVE MEANS THROUGH SAID TRANSMISSION MEANS.